diff options
Diffstat (limited to 'drivers/nvmem/core.c')
-rw-r--r-- | drivers/nvmem/core.c | 316 |
1 files changed, 51 insertions, 265 deletions
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index f24008b66826..c7892c3da91f 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -17,27 +17,7 @@ #include <linux/nvmem-provider.h> #include <linux/of.h> #include <linux/slab.h> - -struct nvmem_device { - struct module *owner; - struct device dev; - int stride; - int word_size; - int id; - struct kref refcnt; - size_t size; - bool read_only; - int flags; - enum nvmem_type type; - struct bin_attribute eeprom; - struct device *base_dev; - struct list_head cells; - nvmem_reg_read_t reg_read; - nvmem_reg_write_t reg_write; - void *priv; -}; - -#define FLAG_COMPAT BIT(0) +#include "nvmem.h" struct nvmem_cell { const char *name; @@ -61,18 +41,7 @@ static LIST_HEAD(nvmem_lookup_list); static BLOCKING_NOTIFIER_HEAD(nvmem_notifier); -static const char * const nvmem_type_str[] = { - [NVMEM_TYPE_UNKNOWN] = "Unknown", - [NVMEM_TYPE_EEPROM] = "EEPROM", - [NVMEM_TYPE_OTP] = "OTP", - [NVMEM_TYPE_BATTERY_BACKED] = "Battery backed", -}; -#ifdef CONFIG_DEBUG_LOCK_ALLOC -static struct lock_class_key eeprom_lock_key; -#endif - -#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev) static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, void *val, size_t bytes) { @@ -91,187 +60,6 @@ static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, return -EINVAL; } -static ssize_t type_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct nvmem_device *nvmem = to_nvmem_device(dev); - - return sprintf(buf, "%s\n", nvmem_type_str[nvmem->type]); -} - -static DEVICE_ATTR_RO(type); - -static struct attribute *nvmem_attrs[] = { - &dev_attr_type.attr, - NULL, -}; - -static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *attr, - char *buf, loff_t pos, size_t count) -{ - struct device *dev; - struct nvmem_device *nvmem; - int rc; - - if (attr->private) - dev = attr->private; - else - dev = container_of(kobj, struct device, kobj); - nvmem = to_nvmem_device(dev); - - /* Stop the user from reading */ - if (pos >= nvmem->size) - return 0; - - if (count < nvmem->word_size) - return -EINVAL; - - if (pos + count > nvmem->size) - count = nvmem->size - pos; - - count = round_down(count, nvmem->word_size); - - rc = nvmem_reg_read(nvmem, pos, buf, count); - - if (rc) - return rc; - - return count; -} - -static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, - struct bin_attribute *attr, - char *buf, loff_t pos, size_t count) -{ - struct device *dev; - struct nvmem_device *nvmem; - int rc; - - if (attr->private) - dev = attr->private; - else - dev = container_of(kobj, struct device, kobj); - nvmem = to_nvmem_device(dev); - - /* Stop the user from writing */ - if (pos >= nvmem->size) - return -EFBIG; - - if (count < nvmem->word_size) - return -EINVAL; - - if (pos + count > nvmem->size) - count = nvmem->size - pos; - - count = round_down(count, nvmem->word_size); - - rc = nvmem_reg_write(nvmem, pos, buf, count); - - if (rc) - return rc; - - return count; -} - -/* default read/write permissions */ -static struct bin_attribute bin_attr_rw_nvmem = { - .attr = { - .name = "nvmem", - .mode = 0644, - }, - .read = bin_attr_nvmem_read, - .write = bin_attr_nvmem_write, -}; - -static struct bin_attribute *nvmem_bin_rw_attributes[] = { - &bin_attr_rw_nvmem, - NULL, -}; - -static const struct attribute_group nvmem_bin_rw_group = { - .bin_attrs = nvmem_bin_rw_attributes, - .attrs = nvmem_attrs, -}; - -static const struct attribute_group *nvmem_rw_dev_groups[] = { - &nvmem_bin_rw_group, - NULL, -}; - -/* read only permission */ -static struct bin_attribute bin_attr_ro_nvmem = { - .attr = { - .name = "nvmem", - .mode = 0444, - }, - .read = bin_attr_nvmem_read, -}; - -static struct bin_attribute *nvmem_bin_ro_attributes[] = { - &bin_attr_ro_nvmem, - NULL, -}; - -static const struct attribute_group nvmem_bin_ro_group = { - .bin_attrs = nvmem_bin_ro_attributes, - .attrs = nvmem_attrs, -}; - -static const struct attribute_group *nvmem_ro_dev_groups[] = { - &nvmem_bin_ro_group, - NULL, -}; - -/* default read/write permissions, root only */ -static struct bin_attribute bin_attr_rw_root_nvmem = { - .attr = { - .name = "nvmem", - .mode = 0600, - }, - .read = bin_attr_nvmem_read, - .write = bin_attr_nvmem_write, -}; - -static struct bin_attribute *nvmem_bin_rw_root_attributes[] = { - &bin_attr_rw_root_nvmem, - NULL, -}; - -static const struct attribute_group nvmem_bin_rw_root_group = { - .bin_attrs = nvmem_bin_rw_root_attributes, - .attrs = nvmem_attrs, -}; - -static const struct attribute_group *nvmem_rw_root_dev_groups[] = { - &nvmem_bin_rw_root_group, - NULL, -}; - -/* read only permission, root only */ -static struct bin_attribute bin_attr_ro_root_nvmem = { - .attr = { - .name = "nvmem", - .mode = 0400, - }, - .read = bin_attr_nvmem_read, -}; - -static struct bin_attribute *nvmem_bin_ro_root_attributes[] = { - &bin_attr_ro_root_nvmem, - NULL, -}; - -static const struct attribute_group nvmem_bin_ro_root_group = { - .bin_attrs = nvmem_bin_ro_root_attributes, - .attrs = nvmem_attrs, -}; - -static const struct attribute_group *nvmem_ro_root_dev_groups[] = { - &nvmem_bin_ro_root_group, - NULL, -}; - static void nvmem_release(struct device *dev) { struct nvmem_device *nvmem = to_nvmem_device(dev); @@ -422,43 +210,6 @@ err: return rval; } -/* - * nvmem_setup_compat() - Create an additional binary entry in - * drivers sys directory, to be backwards compatible with the older - * drivers/misc/eeprom drivers. - */ -static int nvmem_setup_compat(struct nvmem_device *nvmem, - const struct nvmem_config *config) -{ - int rval; - - if (!config->base_dev) - return -EINVAL; - - if (nvmem->read_only) - nvmem->eeprom = bin_attr_ro_root_nvmem; - else - nvmem->eeprom = bin_attr_rw_root_nvmem; - nvmem->eeprom.attr.name = "eeprom"; - nvmem->eeprom.size = nvmem->size; -#ifdef CONFIG_DEBUG_LOCK_ALLOC - nvmem->eeprom.attr.key = &eeprom_lock_key; -#endif - nvmem->eeprom.private = &nvmem->dev; - nvmem->base_dev = config->base_dev; - - rval = device_create_bin_file(nvmem->base_dev, &nvmem->eeprom); - if (rval) { - dev_err(&nvmem->dev, - "Failed to create eeprom binary file %d\n", rval); - return rval; - } - - nvmem->flags |= FLAG_COMPAT; - - return 0; -} - /** * nvmem_register_notifier() - Register a notifier block for nvmem events. * @@ -651,14 +402,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) nvmem->read_only = device_property_present(config->dev, "read-only") || config->read_only || !nvmem->reg_write; - if (config->root_only) - nvmem->dev.groups = nvmem->read_only ? - nvmem_ro_root_dev_groups : - nvmem_rw_root_dev_groups; - else - nvmem->dev.groups = nvmem->read_only ? - nvmem_ro_dev_groups : - nvmem_rw_dev_groups; + nvmem->dev.groups = nvmem_sysfs_get_groups(nvmem, config); device_initialize(&nvmem->dev); @@ -669,7 +413,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) goto err_put_device; if (config->compat) { - rval = nvmem_setup_compat(nvmem, config); + rval = nvmem_sysfs_setup_compat(nvmem, config); if (rval) goto err_device_del; } @@ -696,7 +440,7 @@ err_remove_cells: nvmem_device_remove_all_cells(nvmem); err_teardown_compat: if (config->compat) - device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom); + nvmem_sysfs_remove_compat(nvmem, config); err_device_del: device_del(&nvmem->dev); err_put_device: @@ -1166,7 +910,7 @@ EXPORT_SYMBOL_GPL(nvmem_cell_put); static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf) { u8 *p, *b; - int i, bit_offset = cell->bit_offset; + int i, extra, bit_offset = cell->bit_offset; p = b = buf; if (bit_offset) { @@ -1181,11 +925,16 @@ static void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell, void *buf) p = b; *b++ >>= bit_offset; } - - /* result fits in less bytes */ - if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE)) - *p-- = 0; + } else { + /* point to the msb */ + p += cell->bytes - 1; } + + /* result fits in less bytes */ + extra = cell->bytes - DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE); + while (--extra >= 0) + *p-- = 0; + /* clear msb bits if any leftover in the last byte */ *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0); } @@ -1335,6 +1084,43 @@ int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) EXPORT_SYMBOL_GPL(nvmem_cell_write); /** + * nvmem_cell_read_u16() - Read a cell value as an u16 + * + * @dev: Device that requests the nvmem cell. + * @cell_id: Name of nvmem cell to read. + * @val: pointer to output value. + * + * Return: 0 on success or negative errno. + */ +int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val) +{ + struct nvmem_cell *cell; + void *buf; + size_t len; + + cell = nvmem_cell_get(dev, cell_id); + if (IS_ERR(cell)) + return PTR_ERR(cell); + + buf = nvmem_cell_read(cell, &len); + if (IS_ERR(buf)) { + nvmem_cell_put(cell); + return PTR_ERR(buf); + } + if (len != sizeof(*val)) { + kfree(buf); + nvmem_cell_put(cell); + return -EINVAL; + } + memcpy(val, buf, sizeof(*val)); + kfree(buf); + nvmem_cell_put(cell); + + return 0; +} +EXPORT_SYMBOL_GPL(nvmem_cell_read_u16); + +/** * nvmem_cell_read_u32() - Read a cell value as an u32 * * @dev: Device that requests the nvmem cell. |